Hitherto, there has been proposed a spool valve of this type, including a spool having a large-diameter land portion and a small-diameter land portion, and a housing that houses the spool so as to be movable in the axial direction (see Patent Document 1, for example). In the spool valve, a liquid chamber is defined by respective facing surfaces of the large-diameter land portion and the small-diameter land portion of the spool and the housing, the housing is formed with a control pressure port communicated with the liquid chamber at all times, and a drain port and a supplied pressure port communicated with and discommunicated from the liquid chamber in accordance with movement of the spool, and the spool is moved to regulate a hydraulic pressure supplied to the supplied pressure port to output the regulated hydraulic pressure from the control pressure port. Notches are formed in respective edge portions of the large-diameter land portion and the small-diameter land portion on the liquid chamber side such that the flow rate of a liquid that leaks from the supplied pressure port into the liquid chamber through a space between the edge portion of the small-diameter land portion on the liquid chamber side and the housing and the flow rate of a liquid that leaks from the liquid chamber to the drain port through a space between the edge portion of the large-diameter land portion on the liquid chamber side and the housing generally coincide with each other.